I am just here to clarify the Quranic stance there are two interpretations of Surah 27:8 that go as the following:
But when he came to it, he was called: "Blessed is whosoever is in the fire, and whosoever is round about it!''
meaning, when he came to it, he saw a great and terrifying sight: the fire was burning in a green bush, and the fire was burning ever brighter while the bush was growing ever more green and beautiful. Then he raised his head, and saw that its light was connected to the clouds of the sky.
and the other interpretation says
"It was not a fire, rather it was shining light.''
Musa stood amazed by what he was seeing, and نُودِيَ أَن بُورِكَ مَن فِي النَّارِ (he was called: "Blessed is whosoever is in the fire...''),
"This means, Holy is (whosoever is in the fire).''
وَمَنْ حَوْلَهَا (and whosoever is round about it)
means, of the angels.
then it says:
O Musa! Verily, it is I, Allah, the All-Mighty, the All-Wise.
So this gives a indication that Allah(swt) spoke true the angel what we belief he did time to time and even true prophets(peace be upon them) on occasions.
As for 28:29-30 it doesn't help your argument.
Conclusion:
At the end the verses do not say that either a angel became the bush or that Allah(swt) became the bush but rather that a voice came out of the direction that doesn't imply that the bush was possessed or that the bush came to life.
So there is no contradiction nor a problem wherein you still belief that a circle can be a square on the same time.